Analysis

An Analysis is a snapshot of your current application status. Based on your defined SLIs, it can validate that your SLOs are satisfied, using the data coming from your defined set of KeptnMetricsProvider resources.

The Analysis resource is an instance of an AnalysisDefinition resource which defines specific data like the time for which the analysis should be done and the appropriate values to use for variables that are used in the AnalysisDefinition query.

Synopsis

apiVersion: metrics.keptn.sh/v1
kind: Analysis
metadata:
  name: <name-of-analysis>
spec:
  timeframe: from: <start-time> to: <end-time> | `recent <timespan>`
  args:
    <variable1>: <value1>
    <variable2>: <value2>
    ...
  analysisDefinition:
    name: <name of associated `analysisDefinition` resource
    namespace: <namespace of associated `analysisDefinition` resource
status:
  pass: true | false
  warning: true | false
  raw: <JSON object>
  state: Completed | Progressing

Fields

apiVersion -- API version being used
kind -- Resource type. Must be set to Analysis
metadata
- name -- Unique name of this analysis. Names must comply with the Kubernetes Object Names and IDs specification.
spec
- timeframe (required) -- Specifies the range for the corresponding query in the AnalysisValueTemplate. This can be populated as one of the following:
  - A combination of ‘from’ and ‘to’ to specify the start and stop times for the analysis. These fields follow the RFC 3339 timestamp format.
  - Set the ‘recent’ property to a time span. This causes the Analysis to use data going back that amount of time. For example, if recent: 10m is set, the Analysis studies data from the last ten minutes.
  If neither is set, the Analysis can not be added to the cluster.
- args -- Map of key/value pairs that can be used to substitute variables in the AnalysisValueTemplate query.
- analysisDefinition (required) -- Identify the AnalysisDefinition resource that stores the AnalysisValuesTemplate associated with this Analysis
  - name -- Name of the AnalysisDefinition resource
  - namespace (optional) -- Namespace of the AnalysisDefinition resource. The AnalysisDefinition resource can be located in any namespace. If the namespace is not specified, the analysis controller looks for the AnalysisDefinition resource in the same namespace as the Analysis resource.
- status -- results of this Analysis run, added to the resource by Keptn, based on criteria defined in the AnalysisDefinition resource.
- warning -- Whether the analysis returned a warning.
- raw -- String-encoded JSON object that reports the results of evaluating one or more objectives or metrics. See Interpreting Analysis results for details.
- state -- Set to Completed or Progressing as appropriate.

Interpreting Analysis results

The status.raw field is a string encoded JSON object object that represents the results of evaluating one or more performance objectives or metrics. It shows whether these objectives have passed or failed, their actual values, and the associated scores. In this example, the objectives include response time and error rate analysis, each with its own criteria for passing or failing. The overall evaluation has passed, and no warnings have been issued.

{
    "objectiveResults": [
        {
            "result": {
                "failResult": {
                    "operator": {
                        "greaterThan": {
                            "fixedValue": "500m"
                        }
                    },
                    "fulfilled": false
                },
                "warnResult": {
                    "operator": {
                        "greaterThan": {
                            "fixedValue": "300m"
                        }
                    },
                    "fulfilled": false
                },
                "warning": false,
                "pass": true
            },
            "objective": {
                "analysisValueTemplateRef": {
                    "name": "response-time-p95"
                },
                "target": {
                    "failure": {
                        "greaterThan": {
                            "fixedValue": "500m"
                        }
                    },
                    "warning": {
                        "greaterThan": {
                            "fixedValue": "300m"
                        }
                    }
                },
                "weight": 1
            },
            "value": 0.00475,
            "score": 1
        },
        {
            "result": {
                "failResult": {
                    "operator": {
                        "greaterThan": {
                            "fixedValue": "0"
                        }
                    },
                    "fulfilled": false
                },
                "warnResult": {
                    "operator": {

                    },
                    "fulfilled": false
                },
                "warning": false,
                "pass": true
            },
            "objective": {
                "analysisValueTemplateRef": {
                    "name": "error-rate"
                },
                "target": {
                    "failure": {
                        "greaterThan": {
                            "fixedValue": "0"
                        }
                    }
                },
                "weight": 1,
                "keyObjective": true
            },
            "value": 0,
            "score": 1
        }
    ],
    "totalScore": 2,
    "maximumScore": 2,
    "pass": true,
    "warning": false
}

The meaning of each of these properties is as follows:

objectiveResults: This is an array containing one or more objects, each representing the results of a specific objective or performance metric.

The first item in the array:
- result -- This object contains information about whether the objective has passed or failed. It has two sub-objects:
  - failResult -- Indicates whether the objective has failed. In this case, it checks if a value is greater than 500 milliseconds and it has not been fulfilled (fulfilled: false).
  - warnResult -- Indicates whether the objective has issued a warning. It checks if a value is greater than 300 milliseconds and it has not been fulfilled (fulfilled: false).
- warning (false in this case).
  - pass -- Indicates whether the objective has passed (true in this case).
- objective -- Describes the objective being evaluated. It includes:
  - analysisValueTemplateRef -- Refers to the template used for analysis (response-time-p95).
  - target -- Sets the target values for failure and warning conditions. In this case, failure occurs if the value is greater than 500 milliseconds and warning occurs if it's greater than 300 milliseconds.
  - weight -- Specifies the weight assigned to this objective (weight: 1).
- value -- Indicates the actual value measured for this objective (value: 0.00475).
- score -- Indicates the score assigned to this objective (score: 1).
The second item in the array:
- result -- Similar to the first objective, it checks whether a value is greater than 0 and has not been fulfilled (fulfilled: false). There are no warning conditions in this case.
- objective -- Describes the objective related to error rate analysis.
  - analysisValueTemplateRef -- Refers to the template used for analysis (error-rate).
  - target -- Sets the target value for failure (failure occurs if the value is greater than 0).
  - weight -- Specifies the weight assigned to this objective (weight: 1).
  - keyObjective -- Indicates that this is a key objective (true).
- value -- Indicates the actual value measured for this objective (value: 0).
- score -- Indicates the score assigned to this objective (score: 1).

totalScore -- Represents the total score achieved based on the objectives evaluated (totalScore: 2).

maximumScore -- Indicates the maximum possible score (maximumScore: 2).

pass -- Indicates whether the overall evaluation has passed (true in this case).

warning -- Indicates whether any warnings have been issued during the evaluation (false in this case).

Usage

An Analysis resource specifies a single Analysis run. It specifies the AnalysisValueTemplate resource that defines the calculations to use, the timeframe for which to report information, and values to use for variables for this run.

The result of this analysis stays in the cluster until the Analysis is deleted. That also means that, if another analysis should be performed, the new analysis must be given a new, unique name within the namespace.

To perform an Analysis (or "trigger an evaluation" in Keptn v1 jargon), apply the analysis-instance.yaml file:

kubectl apply -f analysis-instance.yaml -n keptn-lifecycle-poc

Retrieve the current status of the Analysis with the following command:

kubectl get analysis - n keptn-lifecycle-poc

This yields an output that looks like the following:

NAME                ANALYSISDEFINITION      WARNING   PASS
analysis-sample-1   my-project-ad                     true

This shows that the analysis passed successfully.

To get the detailed result of the evaluation, use the -oyaml argument to inspect the full state of the analysis:

This displays the Analysis resource with the definition of the analysis as well as the status (results) of the analysis; for example:

kubectl get analysis - n keptn-lifecycle-poc -oyaml

Examples

apiVersion: metrics.keptn.sh/v1
kind: Analysis
metadata:
  labels:
    app.kubernetes.io/name: analysis
    app.kubernetes.io/instance: analysis-sample
    app.kubernetes.io/part-of: metrics-operator
    app.kubernetes.io/managed-by: kustomize
    app.kubernetes.io/created-by: metrics-operator
  name: analysis-sample
spec:
  timeframe:
    recent: 5m
  args:
    project: my-project
    stage: dev
    service: svc1
    nodename: test # can be any key/value pair; NOT only project/stage/service
  analysisDefinition:
    name: ad-my-proj-dev-svc1
    namespace: keptn-system

This Analysis resource:

Defines the timeframe for which the analysis is done as between 5 am and 10 am on the 5th of May 2023
Adds a few specific key-value pairs that will be substituted in the query. For instance, the query could contain the {{.nodename}} variable. The value of the args.nodename field (test) will be substituted for this string.

For a full example of how to implement the Keptn Analysis feature, see the Analysis guide page.

Files

API reference: Analysis

Differences between versions

The Keptn Analysis feature is an official part of Keptn v0.10.0 and later. Keptn v0.8.3 included a preliminary release of this feature but it was hidden behind a feature flag. The behavior of this feature is unchanged since v0.8.3.